1. Field of the Invention
The present invention relates to a work cutting apparatus and a method for cutting a work, and specifically to a work cutting apparatus and a method for cutting a sintered compact such as a magnet.
2. Description of the Related Art
FIG. 22 shows a conventional work cutting apparatus for obtaining a magnet used in a voice coil motor for example. This work cutting apparatus 1 is an overhang model of a so-called cantilever type. A rotating shaft 2 is mounted with a plurality of cutting blades 3 spaced from each other by spacers (not illustrated). The rotating shaft 2 has an end portion supported by a support arm 4. The work cutting apparatus 1 includes an X-slider 6 slidably placed on rails 5. The X-slider 6 has an upper surface provided with a chuck table 7. The chuck table 7 has an upper surface provided with a pasting board 8. The pasting board 8 has an upper surface placed for example with a plurality of works 9 fixed by an adhesive. Then, the X-slider 6 is slid in a direction shown by an arrow A (along an X axis), so that the works 9 are moved at a constant speed toward the cutting blades 3 rotating in a direction shown by an arrow B, thereby cutting the works 9 into a predetermined thickness. Since the works 9 are cut by the plurality of cutting blades 3, a plurality of magnet pieces are obtained in a single cycle of cutting operation.
In the work cutting apparatus 1, the cutting blades 3 should ideally be mounted at exact right angle to the rotating shaft 2. In such a case, a cutting reaction will only develop within surfaces of the cutting blades, or no force causing the cutting blade 3 to deform vertically to a rotating plane of the cutting blade 3 is generated. Actually however, as shown in FIG. 23, there is involved a cutting blade mounting error θ (θ=0.02˜0.04 degree approx.), and therefore the cutting reaction f. The cutting reaction f includes a tangential component force f1, which includes a component force f2 corresponding to the mounting error (f2=f1×sin θ) acting as the force to deform the cutting blade 3. As a result, the cutting blade 3 is deformed, and cutting accuracy is reduced.
Further, according to the convention, as shown in FIG. 24, a stroke L2 of the cutting blade 3 necessary for the cutting is long, and therefore a long time is required for the cutting operation, posing a problem of poor operability.